A control system configured by a plurality of control units such as an engine ECU (Electronic Control Unit) and a motor ECU has conventionally been known.
In some of such control systems, each control unit has a function of detecting the abnormality in communication between the control units. Therefore, in those cases, for turning off the power of each control unit, the control devices are synchronized with each other in order to prevent the erroneous detection of the abnormality in communication.
For example, Patent Document 1 discloses a technique in which two CPUs (Central Processing Units) synchronize their timing for turning off the power by advancing the process of stopping the power supply while communicating with each other.